Astronomers are saying that the star cluster called Messier 67 is home to unexpectedly high number of hot giant planets.
Findings of a study conducted by an international team of astronomers are suggesting that the star cluster called Messier 67 contains much more hot Jupiter-like planets than the experts originally expected. The said study was carried out using a series of telescopes and equipment including the HARPS spectrograph of La Silla Observatory, Chile.
The team of scientists conducting this study included researchers from Europe, Brazil and Chile and was led by German scientist Roberto Saglia. Saglia and his team invested several years of their life for collecting accurate measurements of the 88 stars forming the Messier 67. Here, it must be mentioned that this star cluster was formed during the same time when the Sun was formed.
The team studies the cluster for traces of hot giant planets using HARPS and a series of other advanced instruments. They tried to spot the wobble experienced by stars due to the presence of giant objects in closed orbits or planets that have hot Jupiter like properties.
Hot Jupiters are actually massive exoplanets boasting mass of more than 33% of Jupiter’s mass. These planets are hot as they are located very near to the parent stars they revolve around. This fact can be proved easily by the short duration of their orbital period or year. Their orbital period lasts for less than 10 days. This makes the hot Jupiters significantly different from the actual giant planet Jupiter. As a result of being located far away from the Sun, the orbital period of Jupiter is 12 Earth years. That’s not all; the planet is also much colder compared to our home planet Earth.
Scientists conducting this new study feel that it’s unlikely that the exotic giants spotted by them were formed in their current location. It’s because the atmosphere near the parent stars wouldn’t have been suitable for formation of these Jupiter-like exoplanets. According to the scientists, all these planets were formed at a place far away from the stars. They started moving towards their parent stars only after they were fully developed. This means there was a time when the planets were cold. This leaves us to wonder what forced these planets to move inwards.
There might be multiple answers to this question, but according to the authors of this new study, the planets started migrating inwards to avoid collisions with neighboring stars.